High Efficiency Cogeneration: Performance Assessment of Industrial Cogeneration Power Plants

Abstract

In 2004, the European Parliament and the Council of the European Union adopted the Directive 2004/8 EC whose purpose is to increase energy efficiency and develop high efficiency cogeneration of heat and power. Italy brought into force this law by means of the Legislative Decree February 8, 2007, n. 20: from January 1, 2011, the high efficiency cogeneration is the cogeneration that meets the requirements of Directive 2004/8/EC. Then, Italy adopted two ministerial decrees: the ministerial decree of Environment Ministry (August 4, 2011), that integrates the Decree n.20, and the ministerial decree of Ministry of Economic Development (September 5, 2011), that lays down the conditions and procedures for access to the support system of cogeneration: for each year in which the requirements of high efficiency cogeneration are met, the cogeneration units are entitled to energy efficiency certificates (White Certificates), whose number is proportional to the energy saving achieved.\ud \ud Therefore, from January 1, 2011 the legislative and incentive cogeneration context is radically changed and, consequently, new boundary conditions must be taken into account for feasibility studies and performance assessments of cogeneration plants. So, in this paper we want to evaluate the impact of this new legislative context on the competitiveness of the various cogeneration technologies. To this end, after an illustration of the new criteria to meet the qualifications of the high efficiency cogeneration, a comparison between different generation technologies will be developed by highlighting the impact of the new incentive context

High-Efficiency Cogeneration Systems: The Case of the Paper Industry in Italy

“…The HEC analysis is conducted by following the guidelines reported in References [7,9,29]. In short, the overall efficiency η g must be calculated as follows:…”

“…Italy implemented the Directive by enacting three decrees [5][6][7], followed by the publication of ministerial guidelines [8]. The authors studied the transposition of the Directive 2004/8 EC in the Italian context, referring to the methodology indicated in the abovementioned guidelines for dealing with cogeneration units in Reference [9]. That paper was an opportunity to better clarify the methodology to evaluate plants in a high-efficiency cogeneration framework and do the groundwork for estimating their primary energy savings, in a similar fashion as the studies carried out by Kanoglu and Dincer [10].…”

Generation Expansion Planning Model for Integrated Energy System Considering Feasible Operation Region and Generation Efficiency of Combined Heat and Power

“…∀ch, ∀bh, ∀t, ∀y. (19) For example, if the electricity generation of the committed CHP resource is within the first boundary segment of Figure 4a, the first boundary segment selecting variable is 1. Then, according to Equation (19), the electricity generation is bigger than P ch,C…”

“…As part of the system, the seasonal variations of energy loads also influence the operation of the CHP resources, whose amount of heat and electricity generation is determined by a heat-to-power ratio. This ratio close to 1 indicates a high overall generation efficiency of the CHP resource [19]. However, during summer, the wasted heat from the CHP resource would increase if the heat-to-power ratio is maintained at constant value.…”

On Selection and Optimal Design of Cogeneration Units in the Industrial Sector

“…In detail, the previous legislation considered the entire electricity production as cogeneration electricity if two parameters, primary energy saving and thermal limit, evaluated on an annual level exceeded specific limit values. According to this previous incentive program, the Italian cogeneration power plants were sized to produce the maximum possible electricity, an analysis conducted by authors [4,5] showed that, up to 2013:…”